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Grinding is a crucial process in machining workpieces because it plays a vital role in achieving the desired precision and surface quality. However, a significant technical challenge in grinding is the potential increase in temperature due to high specific energy, which can lead to surface thermal damage. Therefore, ensuring control over the surface integrity of workpieces during grinding becomes a critical concern. This necessitates the development of temperature field models that consider various parameters, such as workpiece materials, grinding wheels, grinding parameters, cooling methods, and media, to guide industrial production. This study thoroughly analyzes and summarizes grinding temperature field models. First, the theory of the grinding temperature field is investigated, classifying it into traditional models based on a continuous belt heat source and those based on a discrete heat source, depending on whether the heat source is uniform and continuous. Through this examination, a more accurate grinding temperature model that closely aligns with practical grinding conditions is derived. Subsequently, various grinding thermal models are summarized, including models for the heat source distribution, energy distribution proportional coefficient, and convective heat transfer coefficient. Through comprehensive research, the most widely recognized, utilized, and accurate model for each category is identified. The application of these grinding thermal models is reviewed, shedding light on the governing laws that dictate the influence of the heat source distribution, heat distribution, and convective heat transfer in the grinding arc zone on the grinding temperature field. Finally, considering the current issues in the field of grinding temperature, potential future research directions are proposed. The aim of this study is to provide theoretical guidance and technical support for predicting workpiece temperature and improving surface integrity. The temperature field is divided into uniform continuous segment and nonuniform discontinuous counterpart. The heat source distribution model is summarized for different cutting depths. The energy proportional coefficient and convective heat transfer coefficient models are summarized. The application and implementation of temperature field and grinding thermal mode are summarized.

This study investigates how climatological temperature fields in simulations are influenced by the choice of moist thermodynamic formulations. Two formulations were compared: one developed to ensure internal thermodynamic consistency, and a simpler approximation similar to those commonly used in meteorological and climate models. Sensitivity experiments using a global cloud‐resolving model showed that tropical upper‐tropospheric temperatures are approximately 2K higher with the simplified formulation than with the consistent formulation. To understand these discrepancies, we compared vertical temperature structures determined by the moist adiabatic lapse rate for both formulations. The temperature difference reaches about 1.4K at 16‐km altitude for a surface temperature of 300K, consistent with the sensitivity experiments. Analysis of the individual contributions revealed that simplifications in specific heat, latent heat, and saturation vapor pressure produce negative, positive, and positive effects, respectively, which are additive. Furthermore, the temperature difference increases exponentially with surface temperature. These results indicate that the choice of moist thermodynamic formulation has a significant impact on the reproducibility of climate fields.

This study aims to develop a novel calibration device to address the challenges of inadequate temperature field uniformity, significant temperature fluctuation, and less reliability in existing static calibration devices for thin-film thermocouples. In the beginning, a multi-zone high-temperature furnace and the reference end thermostat were designed separately utilizing the three-zone temperature control method and metal block heating together with air-cooled cycle. The finite element analysis method was used to simulate the temperature fields in both the working area of the reference end thermostat and the furnace barrel of a multi-zone high-temperature furnace. The working area’s temperature field environment was simulated and analyzed, which led to determining optimal partition length and heating power ratio of the multi-zone furnace heating wire. Finally, the temperature field in the multi-zone high-temperature furnace and the reference end thermostat were analyzed. The results demonstrated that the multi-zone high-temperature furnace significantly outperformed the conventional single-zone furnace. The uniform temperature field’s length reached 80 mm, with an axial temperature gradient below the 0.4 ℃/10 mm required by the national regulations. Additionally, the reference end thermostat maintained a temperature fluctuation within 0.25 ℃/10 min, which can meet the calibration requirements.

This paper examines the engineering background of the main shaft of Ruihai Mining Group Company in Laizhou City, with a focus on the loose permeable stratum located in the frozen section of the shaft. Field measurements and data collection, including brine temperature and surface subsidence values, were conducted using temperature and hydrological boreholes. The distribution of the frozen wall temperature field was then numerically simulated using finite element analysis, and the results were compared and analyzed with field data. Scanning electron microscopy (SEM) was used to qualitatively describe the microstructure of the soft rock in the frozen section under different freezing schemes. Based on the formation of the frozen wall, a new construction scheme for freezing and excavating the internal and external circles of the vertical shaft in the loose permeable stratum is proposed. This involves the implementation of \"inner and outer double-circles of freezing holes\" and a comparison of the freezing effect of the temperature field before and after the improvement. The results indicate that the new freezing scheme can accelerate the freezing rate of the surrounding rock of the shaft, and reduce the time required for closure by more than 10 days. After applying the improved scheme for 60 days, the temperature is lowered by 4–5 ℃ compared to the original scheme, and the thickness of the frozen wall is approximately 4.8 m, significantly thicker than before. These findings demonstrate the effectiveness of adding an inner circle of freezing holes in achieving the lowest temperature which contributes to subsequent shaft excavation. The new scheme holds significant implications for the safe construction of shaft excavation in complex hydrogeological areas.HighlightsThe main shaft in the unique geological conditions and the impact of tidal activities on freezing performance are analyzed.The new construction scheme incorporating \"inner and outer double-circles of freezing holes\" significantly improves freezing efficiency and reduces closure time.The improved scheme results in a thicker frozen wall and lower temperature compared to the original scheme.The findings have important implications for the safe construction of shaft excavation in complex coastal hydrogeological areas.

Global climate change occurs not only at the ocean surface but also at the ocean bottom, which is the main habitat of demersal fish. To clarify the current status of bottom temperature warming off the Pacific coast of northeastern Japan, we examined gridded bottom temperature fields from 2003 to 2019. These fields were created by a newly developed gridding method using flexible Gaussian filter weighting with time, distance, and depth. Spatially averaged bottom temperature had a strong, significant warming trend of 0.083 to 0.115°C yr−1 in depth zones of 150–300 m, indicating bottom temperature warming. Corresponding to the warming, increases in landing amounts were found for warm-water species such as searobin in the middle region of our study area (37° 50′–39° N). Seasonal catch amounts suggest that ribbon fish and swimming crab recently began to overwinter and reproduce in the area. The distribution shifts of non-target species in fisheries were also analyzed using bottom otter trawl survey data from the area from 2003 to 2019. Northward distribution shifts and increases in density were observed in blackbelly lantern shark and bighand grenadier, indicating that bottom temperature warming led to habitat expansion. Conversely, darkfin sculpin and jelly eelpout shifted northward with decreasing density, suggesting that bottom temperature warming had a negative effect on them. Deepsea bonefish shifted deeper into colder waters with increasing density and mean body weight. Thus, changes and responses of demersal fish to bottom temperature warming in the area were revealed.

With growing global energy demand, deep and ultra-deep wells have become a focal point in oil and gas development. Wellbore temperature variations significantly impact drilling and completion operations in such wells. To analyze the temperature distribution in ultra-deep wellbores, a numerical model based on the Gauss–Seidel iterative algorithm was developed. This model explicitly accounts for the convective heat transfer coefficient and the distinct thermophysical properties of drilling fluids in both the drill string and the annulus. By employing adaptive meshing, it significantly enhances computational efficiency while ensuring accuracy. This study investigated the influence of key parameters—including drilling fluid density, specific heat capacity, drill pipe thermal conductivity, and formation properties—on bottom-hole temperature. The results show that the average deviation between the actual wellbore temperature and the model-predicted temperature is 0.5%. The heat transfer dynamics model for ultra-deep wells is validated by the close agreement between theoretical predictions and field data. This study offers a valuable theoretical basis for wellbore temperature management and the control of drilling fluid cooling systems, supporting safer and more efficient development of ultra-deep resources.

Lamb wave-based damage detection for large-scale composites is one of the most prosperous structural health monitoring technologies for aircraft structures. However, the temperature has a significant effect on the amplitude and phase of the Lamb wave signal so that temperature compensation is always the focus problem. Especially, it is difficult to identify the damage in the aircraft structures when the temperature is not uniform. In this paper, a compensation method for Lamb wave-based damage detection within a non-uniform temperature field is proposed. Hilbert transform and Levenberg-Marquardt optimization algorithm are developed to extract the amplitude and phase variation caused by the change of temperature, which is used to establish a data-driven model for reconstructing the reference signal at a certain temperature. In the temperature compensation process, the current Lamb wave signal of each exciting-sensing path under the estimated structural condition is substituted into the data-driven model to identify an interpolated initial temperature field, which is further processed by an outlier removing algorithm to eliminate the effect of damage and get the actual non-uniform temperature field. Temperature compensation can be achieved by reconstructing the reference signals within the identified non-uniform temperature field, which are used to compare with the current acquired signals for damage imaging. Both simulation and experiment were conducted to verify the feasibility and effectiveness of the proposed non-uniform temperature field identification and compensation technique for Lamb wave-based structural health monitoring.

Before 2008, the number of surface observation stations in China was small. Thus, the surface observation data were too sparse to effectively support the High-resolution China Meteorological Administration’s Land Assimilation System (HRCLDAS) which ultimately inhibited the output of high-resolution and high-quality gridded products. This paper proposes a statistical downscaling model based on a deep learning algorithm in super-resolution to research the above problem. Specifically, we take temperature as an example. The model is used to downscale the 0.0625° × 0.0625°, 2-m temperature data from the China Meteorological Administration’s Land Data Assimilation System (CLDAS) to 0.01° × 0.01°, named CLDASSD. We performed quality control on the paired data from CLDAS and HRCLDAS, using data from 2018 and 2019. CLDASSD was trained on the data from 31 March 2018 to 28 February 2019, and then tested with the remaining data. Finally, extensive experiments were conducted in the Beijing-Tianjin-Hebei region which features complex and diverse geomorphology. Taking the HRCLDAS product and surface observation data as the “true values” and comparing them with the results of bilinear interpolation, especially in complex terrain such as mountains, the root mean square error (RMSE) of the CLDASSD output can be reduced by approximately 0.1°C, and its structural similarity (SSIM) was approximately 0.2 higher. CLDASSD can estimate detailed textures, in terms of spatial distribution, with greater accuracy than bilinear interpolation and other sub-models and can perform the expected downscaling tasks.

As the mining depth of coal mines continues to increase, the problem of mine heat damage becomes increasingly prominent. In response to the heat damage problem in deep mines, this paper presents a novel approach of mine heat damage control and geothermal resource exploitation under the collaborative effect of extraction and ventilation. Taking Sanhejian Coal Mine in Xuzhou as the research object, numerical simulation is conducted using finite element simulation analysis software to analyze the evolution law of the temperature field of roadway surrounding rock and air in the roadway during the variation of different key factors. Additionally, in the process of continuous tunneling, the optimal cooling scheme for roadways at different locations is obtained. The conclusions are as follows: (1) Treating mine heat damage under pure ventilation has the advantage of rapid cooling speed. The temperature at the observation point in the roadway can be reduced to approximately 283 K at its lowest. However, the disadvantage lies in the large temperature difference before and after the roadway (no less than 7 K) and the need for continuous ventilation. (2) During the extraction process, reducing the average injection water temperature and decreasing the distance from the roadway can effectively enhance the effectiveness of mine heat damage control. Nevertheless, under pure extraction, the temperature reduction rate of roadway surrounding rock is relatively slow. When the distance between the roadway and the injection well does not exceed 30 m and the average injection water temperature does not exceed 190 K, the surrounding rock temperature can be reduced to below 303.15 K within one year. (3) The extraction-ventilation synergy method not only can effectively narrow the temperature difference before and after the roadway but also can improve the temperature reduction speed in the roadway to a certain extent. Moreover, the geothermal resources generated by extraction can also yield certain economic benefits. This research provides a new perspective for cooling the coal mining face of coal mines.

In the construction of an F‐type cross‐passage in an overlapping‐type shield tunnel using the artificial ground freezing method, the development of the distal frozen wall is difficult to control, and ground deformation is influenced by the superimposed disturbance of successive construction steps. Existing studies are insufficient to fully characterize the evolution of the frozen temperature field and frozen displacement field. To address this, the F‐type cross‐passage between Lingbi Road Station and Yaoyuan Road Station of Hefei Metro Line 8 adopted measures such as installing inclined freeze pipes for reinforcement and applying time‐sequence construction to control the distal cooling capacity and ground displacement field. Numerical simulation combined with analysis of field test data was conducted to investigate the evolution laws of the frozen temperature field and frozen displacement field in this F‐type cross‐passage. The results indicate that by installing long inclined freeze pipes on both sides of the main frozen reinforcement zone, the minimum thickness of the frozen wall at the control section ( X = −12.03 m) reached 2.51 m after 55 days of active freezing, satisfying the design requirements. At the same time, after 55 days of ground freezing, the soil temperature in the central region of the Y = 0 m section ranged from 2.5°C to −2.5°C. This indicates that the soil was at the critical freezing temperature, which is favorable for the underground excavation of the F‐type cross‐passage. Regarding ground deformation, during both the freezing reinforcement and excavation stages, a pancake‐shaped heave/settlement zone appeared on the surface above the cross‐passage, with slight shifts in its center position. The surface displacement field generally showed a decreasing or increasing trend outward from this central position.